no loop, no conditional statement, no brute force to print out 1 to 1000

print1-1000.cpp

#include <iostream>
#include <functional>

int main()
{
    std::function<void(int)> a[2];
    // lambda: [&capture](parameters)->return_type {body}
    a[0] = [&](int i) {std::cout << i << std::endl; a[i/1000](i+1);};
    a[1] = [](int i) {return;};
    a[0](1);
    return 0;
}